Background: The aim of this in vitro study was to evaluate and compare the effect of preheating microleakage among three different filler size composites which include Filtek^tm Z250 micro hybrid, Z250^xt Nano hybrid and nanocomposite Z350^xt.  in Class II cavity preparation .

Materials and methods: sixty maxillary first premolars were prepared with class II cavities. Samples were divided into three groups according to material used    group A (FiltekZ250 micro hybrid). Group B(Z250^xt Nano hybrid). Group C (nanocomposite Z350^xt)and each group divided into two subgroups of ten teeth according to temperature of  composite:

This study deals with the corrosion inhibition of metal corrosion process of medium carbon steel using 1M HCl for kinetic studies and rate reaction determination. The weight loss method is applied to pieces of Medium carbon steel divided to Cubans with dimensions (0.4*2*2.4) cm , and use Tafel Extrapolation Method, the samples were polished using carbide silicon paper with dimensions of (180,200,400,600,800,1000). The samples were immersed in the alcoholic medium ethanol at a temperature 293K for 3hr. Natural inhibitor Kujarat Tea (Hibiscus sabdarriffa L.) is used which is extracted in aqueous and alcoholic medium, different concentrations (1000،2000, 3000) ppm have been used ; The best concentration found through the results is a

The present study aims to evaluate the effects of methotrexate (MTX) with and without vitamin A (Vit. A) on some biochemical parameters and histological structure in male rabbits liver. Twenty male rabbits weighing 1250-1480 gm were divided into four equal number groups. The first group was given 2 ml distilled water as control group. The second group was given MTX (20 mg/kg), the third group was given Vit. A (5000 IU), while the fourth group was given MTX (20 mg/kg) +Vit. A (5000 IU) in alternative days. Following four weeks of treatment, lipid profile total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL), [low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL)]; in addition to thyroid hormones tr

In the present work, the critical micelle concentration (CMC) of the solution of Sodium dodecyl sulfate (SDS) as anionic surfactant, Cocamidopropyl Betaine (CAPB) as amphoteric surfactant, and their mixture have been determined using surface tension and conductivity measurements at a temperature range 293 -323 K. The adsorption and thermodynamic micellization parameters (?G?m, ?G?ads, ?max ,Amin,?cmc ) for individual surfactants was calculated. Rosen model which is focuses on the adsorbed mixed surfactant film at the air/solution interface was used to calculate the interaction parameter ( ?? ) at the interface and the activity coefficients g1 and g2. The results indicate that the CMC of the individual surfactants was affected by

Objective: The aim of this study was to assess the knowledge and attitude of Iraqi dentists towards cone beam computed tomography (CBCT) applications in endodontics by using an online survey. Materials and Methods: A questionnaire, consisting of 31 questions, targeted general dental practitioners and specialists in different dental specialities. A total of 306 participants were included. Data were assessed according to the frequency of distribution and the chi-square test was applied to analyse the difference in responses between two independent groups. Results: Among the participants 63.4% were using digital radiography in their daily practice, and 84% had awareness about CBCT's uses, with higher statistically significant responses among e

Background: The formation of white spot lesions around fixed orthodontic attachments is a common complication during and after fixed orthodontic treatment, which hinders the result of a successfully completed orthodontic treatment. The aim of the study was to assess the effectiveness of the Caries Infiltrant (ICON®) on prevention of caries on the smooth enamel surface when applied alone or combined with conventional adhesives. Materials and methods: Seventy eight human premolar enamel discs were randomly assigned to six groups (n=13). The discs were etched and treated with resins of different monomer content forming the following groups: (1)Untreated etched samples served as the negative control, (2) ICON® (DMG), (3) Adper™ S

The main objective of this study is to determine whether the use of He-Ne Laser (632.8 nm wavelength and power 0.5 mW) is an eligible and effective tool to kill or reduce the cell viability of Candida albicans isolated from complete upper dentures. Twenty one swabs were taken from the complete upper dentures. Only six swabs showed positive cultures for C. albicans. The isolate was divided into two groups, group I was not irradiated (control), and group II was irradiated by He-Ne Laser for different periods (10, 15, 20, and 30) min. After irradiation, the results showed a significant reduction in the viable cell count and colonies diameters especially at exposure periods 10 and 15 min. Although the low power He-Ne Laser was not eradicating t

It is through a review of conversion of vegetable oils into glycidyl ethers focusing on their roles in achieving sustainability and improved epoxy resin performance. It involves functionalization of triglycerides in the form of epoxidation followed by glycidylation and yields bio-based monomers having improved mechanical as well as thermal properties. The review covers the underlying chemistry, production drivers, industrial applications, and future issues, supported by quantitative data and comparative studies. In addition, it integrates recent data on catalyst choice, feedstock flexibility, and environmental performance factors of bio-based resins, indicating their suitability for replacing traditional petroleum-based components.<

In this work we prepared some schiff bases by condensation urea and benzaldehyde or its derevative ( bromo benzaldehyde or hydroxy benzaldehyde ) as ( 1 : 1 ) mole ( urea : benzaldehyde or its substitution ) to prepare compounds ( A1 , B1 , C1 , D1 , E1 , F1 , G1 ) and ( 1 : 2 ) mole ( urea : benzaldehyde or its substitution ) to prepare compounds ( A2 , B2 , C2 , D2 , E1 , F2 , G2 ) . The prepared compounds identified spectroscopic by infrared spectroscopy FT-IR and Thin layer chromotography T.L.C . The force constant calculated from the wave number for the carbonyl stretching from FT-IR chart and by using the following equation K = 4?2C2?'2? The change in double bond order for carbonyl deteremined in according with some past re